view contrib/python-zstandard/zstd/common/pool.h @ 47592:0f5c203eb5ab

dirstate: add a function to update tracking status while "moving" parents

The `scmutil.dirstateparent` is moving the dirstate parent without touching the
working copy. It is used by history-rewriting operations like amending of
folding.

The function was directly doing the "low level" computation and dirstate
change.  All that logic belong to the dirstate and should be moved there.

For this purpose we introduce a new function that does just that and use it.

Differential Revision: https://phab.mercurial-scm.org/D11012

/*
 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef POOL_H
#define POOL_H

#if defined (__cplusplus)
extern "C" {
#endif


#include <stddef.h>   /* size_t */
#define ZSTD_STATIC_LINKING_ONLY   /* ZSTD_customMem */
#include "zstd.h"

typedef struct POOL_ctx_s POOL_ctx;

/*! POOL_create() :
 *  Create a thread pool with at most `numThreads` threads.
 * `numThreads` must be at least 1.
 *  The maximum number of queued jobs before blocking is `queueSize`.
 * @return : POOL_ctx pointer on success, else NULL.
*/
POOL_ctx* POOL_create(size_t numThreads, size_t queueSize);

POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize,
                               ZSTD_customMem customMem);

/*! POOL_free() :
 *  Free a thread pool returned by POOL_create().
 */
void POOL_free(POOL_ctx* ctx);

/*! POOL_resize() :
 *  Expands or shrinks pool's number of threads.
 *  This is more efficient than releasing + creating a new context,
 *  since it tries to preserve and re-use existing threads.
 * `numThreads` must be at least 1.
 * @return : 0 when resize was successful,
 *           !0 (typically 1) if there is an error.
 *    note : only numThreads can be resized, queueSize remains unchanged.
 */
int POOL_resize(POOL_ctx* ctx, size_t numThreads);

/*! POOL_sizeof() :
 * @return threadpool memory usage
 *  note : compatible with NULL (returns 0 in this case)
 */
size_t POOL_sizeof(POOL_ctx* ctx);

/*! POOL_function :
 *  The function type that can be added to a thread pool.
 */
typedef void (*POOL_function)(void*);

/*! POOL_add() :
 *  Add the job `function(opaque)` to the thread pool. `ctx` must be valid.
 *  Possibly blocks until there is room in the queue.
 *  Note : The function may be executed asynchronously,
 *         therefore, `opaque` must live until function has been completed.
 */
void POOL_add(POOL_ctx* ctx, POOL_function function, void* opaque);


/*! POOL_tryAdd() :
 *  Add the job `function(opaque)` to thread pool _if_ a worker is available.
 *  Returns immediately even if not (does not block).
 * @return : 1 if successful, 0 if not.
 */
int POOL_tryAdd(POOL_ctx* ctx, POOL_function function, void* opaque);


#if defined (__cplusplus)
}
#endif

#endif